The Experts below are selected from a list of 3420 Experts worldwide ranked by ideXlab platform

Yukihiko Nosé - One of the best experts on this subject based on the ideXlab platform.

  • ECCENTRIC Inlet Port OF THE PIVOT BEARING SUPPortED GYRO CENTRIFUGAL PUMP
    Artificial Organs, 2008
    Co-Authors: Yoshiyuki Takami, Aron José Pazin De Andrade, Tadashi Nakazawa, Kenzo Makinouchi, Robert Benkowski, Julie Glueck, Yukihiko Nosé
    Abstract:

    : An eccentric Inlet Port is a unique feature of the pivot bearing supPorted Gyro Compact-1 Eccentric Inlet Port Model 3 (ClE3) centrifugal pump, a completely seal-less centrifugal pump. The latest C1E3 has an eccentric Inlet Port with a 30 degree vertical angle. To investigate the adequacy of this 30 degree angle, flow visualization studies and in vitro hemolysis tests were performed, comparing 4 pumps, each with a different angle of the eccentric Inlet Port (0, 30, 60, and 90 degrees). The flow visualization study utilizing a tracer method focused on the flow pattern just distal to the Inlet Port of each pump, and each pump was operated at 5 L/min against 100 mm Hg and 5 L/min against 350 mm Hg. In the pumps with angles of 90 and 60 degrees, the flow direction changed horizontally, causing a vortex formation. In the pump with the 30 degree angle, the inflow did not change its course, resulting in minimal space for vortex formation. In the pump with the 0 degree angle, the inflow collided with the pump housing, resulting in a small vortex formation along the housing surface. The in vitro hemolysis tests at 5 L/min against 350 mm Hg revealed that the pump with the 30 degree angle was the least hemolytic and the pump with the 90 degree angle was the most hemolytic among the 4 pumps. These results suggest that the angle of the eccentric Inlet Port of the Gyro C1E3 pump should be 30 degrees to have less vortex formation and less red blood cell trauma.

  • Hydraulic assessment of the floating impeller phenomena in a centrifugal pump.
    Artificial Organs, 2008
    Co-Authors: Tadashi Nakazawa, Yoshiyuki Takami, Kenzo Makinouchi, Robert Benkowski, Julie Glueck, George Damm, Yukihiko Nosé
    Abstract:

    : A compact eccentric Inlet Port centrifugal blood pump (C1E3) has been perfected for a long-term centrifugal ventricular assist device as well as a cardiopulmonary bypass pump. The C1E3 pump incorporates a sealless design and a blood stagnation free structure. The pump's impeller is magnetically coupled to the driver magnet in a sealless manner. The latest hemolysis study reveals that hemolysis is affected by the magnetic coupling distance between the driver and impeller magnet. Furthermore, a floating phenomenon can be observed in a pivot bearing supPorted pump. Attention was focused on the relationship between the floating phenomenon's characteristics and the magnetic coupling design in the C1E3 pump. Studies were conducted to evaluate the hydromechanical performance in the floating phenomenon. In this study, the relationship between the magnetic coupling design and the floating phenomenon was verified with a smooth spinning condition. The optimized magnetic coupling distance for the floating mode was estimated to be 12 mm for left ventricular assist device and 9 mm for cardiopulmonary bypass pump. Obtaining an optimal spinning condition is required for regulating the magnetic coupling force. To develop a double pivot bearing pump, it is necessary to establish an optimal spinning and/or floating condition and to determine the proper magnetic coupling and magnetic force between the impeller and driver.

  • current status of the gyro centrifugal blood pump development of the permanently implantable centrifugal blood pump as a biventricular assist device nedo project
    Artificial Organs, 2004
    Co-Authors: Yukihiko Nosé, Kojiro Furukawa
    Abstract:

    : The New Energy and Industrial Technology Development Organization (NEDO) project was started in 1995. The goal is the development of a multipurpose, totally implantable biventricular assist device (BVAD) that can be used for any patient who suffers from severe heart failure. Our C1E3 (two-week pump) centrifugal pump, called the Gyro pump, has three design characteristics: a magnetic coupling and double pivot bearing system, an eccentric Inlet Port, and secondary vanes on the bottom of the impeller. The pump was miniaturized. The C1E3 evolved into the NEDO PI-601, a totally implantable centrifugal pump for BVAD. The current NEDO PI-710 pump (five-year pump) system includes a centrifugal pump with pivot bearings, a hydraulically-levitated impeller, an rpm-controlled miniaturized actuator (all-in-one actuator plus controller), an emergency clamp on the left outflow, and a Frank–Starling-type flow control. The final mass production model is now finalized, and the final animal study  and  two-year  endurance  studies are ongoing.

  • flow visualization in a centrifugal blood pump with an eccentric Inlet Port
    Artificial Organs, 2004
    Co-Authors: Takashi Yamane, Takayuki Kodama, Yoshiro Yamamoto, Toshiyuki Shinohara, Yukihiko Nosé
    Abstract:

    Flow visualization analysis was applied to the Baylor/Miwatec centrifugal artificial heart to evaluate its fluid dynamic characteristics regarding antithrombogenicity. An eccentric vortex was found both in the upper and the lower gaps of the impeller, which is supposed to be caused by the eccentric Inlet Port. Therefore, one-way flow toward the outlet is formed and washes the pivot. The combination of an eccentric vortex and a pivot bearing that is washed is unique to the Baylor/Miwatec pump. For the male pivots exposed to periodic wash, the minimum shear rate around the bottom pivot was estimated to be 650/s, which is higher than the threshold for thrombus formation shown by other studies. The wall shear rate at the impeller bottom surface was found to be larger in the top contact mode than in the bottom contact mode.

  • Development and evaluation of antithrombogenic centrifugal pump : the Baylor C-Gyro Pump eccentric Inlet Port model
    Artificial organs, 1994
    Co-Authors: Yasuhisa Ohara, Kenzo Makinouchi, Julie Glueck, Byron Sutherland, Takatsugu Shimono, Kozo Naito, Kimitaka Tasai, Yukihiko Orime, Setsuo Takatani, Yukihiko Nosé
    Abstract:

    The Baylor C-Gyro Pump Eccentric Inlet Port Models (C1E) have been developed aiming for a long-term centrifugal ventricular assist device (VAD) as well as a cardiopulmonary bypass pump. The eccentric Inlet Port models are characterized by their unique Inlet Port and secondary impeller vanes. An Inlet female pivot bearing, which was fixed to a supPorting bar in the prototype model, is directly embedded into the ceiling of the pump casing. An Inlet Port is then placed off-center to avoid the bearing area, and it is angled between 0 to 90 degrees from the upright position. In addition, small secondary vanes were incorporated into the impeller bottom to accelerate the washout flow behind the impeller. These features attained design objectives proposed for higher antithrombogenicity: a seal-less pump chamber, no stationary parts in the blood path, and acceleration of the secondary flow behind the impeller. The first in vivo experiment using C1E pumps showed excellent antithrombogenicity for up to 18 days when the experiment ceased due to severe infection in the calf.

Kenzo Makinouchi - One of the best experts on this subject based on the ideXlab platform.

  • ECCENTRIC Inlet Port OF THE PIVOT BEARING SUPPortED GYRO CENTRIFUGAL PUMP
    Artificial Organs, 2008
    Co-Authors: Yoshiyuki Takami, Aron José Pazin De Andrade, Tadashi Nakazawa, Kenzo Makinouchi, Robert Benkowski, Julie Glueck, Yukihiko Nosé
    Abstract:

    : An eccentric Inlet Port is a unique feature of the pivot bearing supPorted Gyro Compact-1 Eccentric Inlet Port Model 3 (ClE3) centrifugal pump, a completely seal-less centrifugal pump. The latest C1E3 has an eccentric Inlet Port with a 30 degree vertical angle. To investigate the adequacy of this 30 degree angle, flow visualization studies and in vitro hemolysis tests were performed, comparing 4 pumps, each with a different angle of the eccentric Inlet Port (0, 30, 60, and 90 degrees). The flow visualization study utilizing a tracer method focused on the flow pattern just distal to the Inlet Port of each pump, and each pump was operated at 5 L/min against 100 mm Hg and 5 L/min against 350 mm Hg. In the pumps with angles of 90 and 60 degrees, the flow direction changed horizontally, causing a vortex formation. In the pump with the 30 degree angle, the inflow did not change its course, resulting in minimal space for vortex formation. In the pump with the 0 degree angle, the inflow collided with the pump housing, resulting in a small vortex formation along the housing surface. The in vitro hemolysis tests at 5 L/min against 350 mm Hg revealed that the pump with the 30 degree angle was the least hemolytic and the pump with the 90 degree angle was the most hemolytic among the 4 pumps. These results suggest that the angle of the eccentric Inlet Port of the Gyro C1E3 pump should be 30 degrees to have less vortex formation and less red blood cell trauma.

  • Hydraulic assessment of the floating impeller phenomena in a centrifugal pump.
    Artificial Organs, 2008
    Co-Authors: Tadashi Nakazawa, Yoshiyuki Takami, Kenzo Makinouchi, Robert Benkowski, Julie Glueck, George Damm, Yukihiko Nosé
    Abstract:

    : A compact eccentric Inlet Port centrifugal blood pump (C1E3) has been perfected for a long-term centrifugal ventricular assist device as well as a cardiopulmonary bypass pump. The C1E3 pump incorporates a sealless design and a blood stagnation free structure. The pump's impeller is magnetically coupled to the driver magnet in a sealless manner. The latest hemolysis study reveals that hemolysis is affected by the magnetic coupling distance between the driver and impeller magnet. Furthermore, a floating phenomenon can be observed in a pivot bearing supPorted pump. Attention was focused on the relationship between the floating phenomenon's characteristics and the magnetic coupling design in the C1E3 pump. Studies were conducted to evaluate the hydromechanical performance in the floating phenomenon. In this study, the relationship between the magnetic coupling design and the floating phenomenon was verified with a smooth spinning condition. The optimized magnetic coupling distance for the floating mode was estimated to be 12 mm for left ventricular assist device and 9 mm for cardiopulmonary bypass pump. Obtaining an optimal spinning condition is required for regulating the magnetic coupling force. To develop a double pivot bearing pump, it is necessary to establish an optimal spinning and/or floating condition and to determine the proper magnetic coupling and magnetic force between the impeller and driver.

  • Development and evaluation of antithrombogenic centrifugal pump : the Baylor C-Gyro Pump eccentric Inlet Port model
    Artificial organs, 1994
    Co-Authors: Yasuhisa Ohara, Kenzo Makinouchi, Julie Glueck, Byron Sutherland, Takatsugu Shimono, Kozo Naito, Kimitaka Tasai, Yukihiko Orime, Setsuo Takatani, Yukihiko Nosé
    Abstract:

    The Baylor C-Gyro Pump Eccentric Inlet Port Models (C1E) have been developed aiming for a long-term centrifugal ventricular assist device (VAD) as well as a cardiopulmonary bypass pump. The eccentric Inlet Port models are characterized by their unique Inlet Port and secondary impeller vanes. An Inlet female pivot bearing, which was fixed to a supPorting bar in the prototype model, is directly embedded into the ceiling of the pump casing. An Inlet Port is then placed off-center to avoid the bearing area, and it is angled between 0 to 90 degrees from the upright position. In addition, small secondary vanes were incorporated into the impeller bottom to accelerate the washout flow behind the impeller. These features attained design objectives proposed for higher antithrombogenicity: a seal-less pump chamber, no stationary parts in the blood path, and acceleration of the secondary flow behind the impeller. The first in vivo experiment using C1E pumps showed excellent antithrombogenicity for up to 18 days when the experiment ceased due to severe infection in the calf.

  • an ultimate compact seal less centrifugal ventricular assist device baylor c gyro pump
    Artificial Organs, 1994
    Co-Authors: Yasuhisa Ohara, Kenzo Makinouchi, Julie Glueck, Takatsugu Shimono, Kozo Naito, Kimitaka Tasai, Yukihiko Orime, Kazumi Mizuguchi, George Damm, Setsuo Takatani
    Abstract:

    We have developed a compact, seal-less, all-purpose centrifugal pump, the Baylor C-Gyro pump, which is intended as a long-term ventricular assist device (VAD) as well as a cardiopulmonary bypass pump. In attaining this goal, we began with eliminating the shaft seals by adopting a pivot bearing system at the impeller shaft. In addition, a ring magnet encased in the bottom of the impeller was coupled magnetically to a driver magnet placed outside the pump housing (C1 Prototype). This first model yielded satisfactory performance in vitro with a flow rate of 8 L/min against 250 mm Hg at 2,400 rpm, and an index of hemolysis (IH) of 0.0083 g/100 L using bovine blood. In the second model, the C1 Eccentric Inlet Port Model, the Inlet bearing supPort bar in the prototype were eliminated without reducing the prototype's performance. These designs for antithrombogenicity are being tested by the first in vivo experiment, which has lasted for more than 2 weeks.

Julie Glueck - One of the best experts on this subject based on the ideXlab platform.

  • ECCENTRIC Inlet Port OF THE PIVOT BEARING SUPPortED GYRO CENTRIFUGAL PUMP
    Artificial Organs, 2008
    Co-Authors: Yoshiyuki Takami, Aron José Pazin De Andrade, Tadashi Nakazawa, Kenzo Makinouchi, Robert Benkowski, Julie Glueck, Yukihiko Nosé
    Abstract:

    : An eccentric Inlet Port is a unique feature of the pivot bearing supPorted Gyro Compact-1 Eccentric Inlet Port Model 3 (ClE3) centrifugal pump, a completely seal-less centrifugal pump. The latest C1E3 has an eccentric Inlet Port with a 30 degree vertical angle. To investigate the adequacy of this 30 degree angle, flow visualization studies and in vitro hemolysis tests were performed, comparing 4 pumps, each with a different angle of the eccentric Inlet Port (0, 30, 60, and 90 degrees). The flow visualization study utilizing a tracer method focused on the flow pattern just distal to the Inlet Port of each pump, and each pump was operated at 5 L/min against 100 mm Hg and 5 L/min against 350 mm Hg. In the pumps with angles of 90 and 60 degrees, the flow direction changed horizontally, causing a vortex formation. In the pump with the 30 degree angle, the inflow did not change its course, resulting in minimal space for vortex formation. In the pump with the 0 degree angle, the inflow collided with the pump housing, resulting in a small vortex formation along the housing surface. The in vitro hemolysis tests at 5 L/min against 350 mm Hg revealed that the pump with the 30 degree angle was the least hemolytic and the pump with the 90 degree angle was the most hemolytic among the 4 pumps. These results suggest that the angle of the eccentric Inlet Port of the Gyro C1E3 pump should be 30 degrees to have less vortex formation and less red blood cell trauma.

  • Hydraulic assessment of the floating impeller phenomena in a centrifugal pump.
    Artificial Organs, 2008
    Co-Authors: Tadashi Nakazawa, Yoshiyuki Takami, Kenzo Makinouchi, Robert Benkowski, Julie Glueck, George Damm, Yukihiko Nosé
    Abstract:

    : A compact eccentric Inlet Port centrifugal blood pump (C1E3) has been perfected for a long-term centrifugal ventricular assist device as well as a cardiopulmonary bypass pump. The C1E3 pump incorporates a sealless design and a blood stagnation free structure. The pump's impeller is magnetically coupled to the driver magnet in a sealless manner. The latest hemolysis study reveals that hemolysis is affected by the magnetic coupling distance between the driver and impeller magnet. Furthermore, a floating phenomenon can be observed in a pivot bearing supPorted pump. Attention was focused on the relationship between the floating phenomenon's characteristics and the magnetic coupling design in the C1E3 pump. Studies were conducted to evaluate the hydromechanical performance in the floating phenomenon. In this study, the relationship between the magnetic coupling design and the floating phenomenon was verified with a smooth spinning condition. The optimized magnetic coupling distance for the floating mode was estimated to be 12 mm for left ventricular assist device and 9 mm for cardiopulmonary bypass pump. Obtaining an optimal spinning condition is required for regulating the magnetic coupling force. To develop a double pivot bearing pump, it is necessary to establish an optimal spinning and/or floating condition and to determine the proper magnetic coupling and magnetic force between the impeller and driver.

  • Development and evaluation of antithrombogenic centrifugal pump : the Baylor C-Gyro Pump eccentric Inlet Port model
    Artificial organs, 1994
    Co-Authors: Yasuhisa Ohara, Kenzo Makinouchi, Julie Glueck, Byron Sutherland, Takatsugu Shimono, Kozo Naito, Kimitaka Tasai, Yukihiko Orime, Setsuo Takatani, Yukihiko Nosé
    Abstract:

    The Baylor C-Gyro Pump Eccentric Inlet Port Models (C1E) have been developed aiming for a long-term centrifugal ventricular assist device (VAD) as well as a cardiopulmonary bypass pump. The eccentric Inlet Port models are characterized by their unique Inlet Port and secondary impeller vanes. An Inlet female pivot bearing, which was fixed to a supPorting bar in the prototype model, is directly embedded into the ceiling of the pump casing. An Inlet Port is then placed off-center to avoid the bearing area, and it is angled between 0 to 90 degrees from the upright position. In addition, small secondary vanes were incorporated into the impeller bottom to accelerate the washout flow behind the impeller. These features attained design objectives proposed for higher antithrombogenicity: a seal-less pump chamber, no stationary parts in the blood path, and acceleration of the secondary flow behind the impeller. The first in vivo experiment using C1E pumps showed excellent antithrombogenicity for up to 18 days when the experiment ceased due to severe infection in the calf.

  • an ultimate compact seal less centrifugal ventricular assist device baylor c gyro pump
    Artificial Organs, 1994
    Co-Authors: Yasuhisa Ohara, Kenzo Makinouchi, Julie Glueck, Takatsugu Shimono, Kozo Naito, Kimitaka Tasai, Yukihiko Orime, Kazumi Mizuguchi, George Damm, Setsuo Takatani
    Abstract:

    We have developed a compact, seal-less, all-purpose centrifugal pump, the Baylor C-Gyro pump, which is intended as a long-term ventricular assist device (VAD) as well as a cardiopulmonary bypass pump. In attaining this goal, we began with eliminating the shaft seals by adopting a pivot bearing system at the impeller shaft. In addition, a ring magnet encased in the bottom of the impeller was coupled magnetically to a driver magnet placed outside the pump housing (C1 Prototype). This first model yielded satisfactory performance in vitro with a flow rate of 8 L/min against 250 mm Hg at 2,400 rpm, and an index of hemolysis (IH) of 0.0083 g/100 L using bovine blood. In the second model, the C1 Eccentric Inlet Port Model, the Inlet bearing supPort bar in the prototype were eliminated without reducing the prototype's performance. These designs for antithrombogenicity are being tested by the first in vivo experiment, which has lasted for more than 2 weeks.

Denys Nicolosi - One of the best experts on this subject based on the ideXlab platform.

  • new centrifugal blood pump with dual impeller and double pivot bearing system wear evaluation in bearing system performance tests and preliminary hemolysis tests
    Artificial Organs, 2008
    Co-Authors: Eduardo Bock, Adriana Ribeiro, Maxwell Silva, Pedro Antunes, Jeison Fonseca, Daniel Legendre, Juliana De Moraes Leme, Celso Arruda, Jose F Biscegli, Denys Nicolosi
    Abstract:

    A new dual impeller centrifugal blood pump has been developed as a research collaboration between Baylor College of Medicine and Institute Dante Pazzanese of Cardiology for long-term left ventricle assist device (LVAD). A design feature of this new pump is a dual impeller that aims to minimize a stagnant flow pattern around the Inlet Port. Several different materials were tested in order to adopt a double pivot bearing design originally developed by Prof. Dr. Yukihiko Nose from Baylor College of Medicine. Hydraulic performance tests were conducted with two different Inlet Ports' angle configurations 30 degrees and 45 degrees . Pump with Inlet Port angle of 45 degrees achieved best values of pressure ahead and flow after 1800 rpm. Preliminary hemolysis tests were conducted using human blood. The pump showed good performance results and no alarming trace of hemolysis, proving to be a feasible long-term LVAD.

D D Ganji - One of the best experts on this subject based on the ideXlab platform.

  • effect of water based al2o3 nanofluids on heat transfer and pressure drop in periodic mixed convection inside a square ventilated cavity
    International Communications in Heat and Mass Transfer, 2011
    Co-Authors: E Sourtiji, S F Hosseinizadeh, M Gorjibandpy, D D Ganji
    Abstract:

    Abstract A numerical study of unsteady mixed convection flows through an alumina-water nanofluid in a square cavity with Inlet and outlet Ports due to incoming flow oscillation is performed. It is found that an oscillating velocity at the Inlet Port cased to creating a periodic variation in the fluid flow and temperature field in the cavity after a certain time duration. The influence of the nanoparticle on the flow and temperature fields has been plotted and discussed. The effect of the oscillation frequency is concealed in a dimensionless number which is the Strouhal number. It is observed that the heat transfer is enhanced for all the Strouhal and Richardson numbers investigated by adding the nanoparticle to the base fluid. It is also found that the performance of the nanoparticle on the enhancement of the heat transfer at higher Richardson numbers is less than that of lower Richardson numbers.

  • heat transfer enhancement of mixed convection in a square cavity with Inlet and outlet Ports due to oscillation of incoming flow
    International Communications in Heat and Mass Transfer, 2011
    Co-Authors: E Sourtiji, S F Hosseinizadeh, M Gorjibandpy, D D Ganji
    Abstract:

    Abstract A numerical study of unsteady laminar mixed convection flow in a square cavity with ventilation Ports due to an oscillating velocity at the Inlet Port is performed. It is found that after certain time duration, a periodic variation in the fluid flow and temperature field in the cavity are created. It is observed that the heat transfer is enhanced for all the Strouhal numbers investigated in comparison to its steady state case. To realize the optimizing Strouhal number to reach the best performance of the system, the total Nusselt number and the coefficient of pressure drop in a cycle of the oscillation is evaluated with respect to the Strouhal number. It is found that for a region of the Strouhal number between 0.5 and 1, the performance of the system will be desirable with considering both the maximum heat transfer rate and minimum pressure drop in the cavity.